A projectile is in the x y plane with the x axis horizontal and $y$ axis vertical. Its velocity of p

Question

A projectile is in the x y plane with the x axis horizontal and $y$ axis vertical. Its velocity of projection is given by\ $v=4.9 j+3 i$. Then the time of flight is\

Professor PC Thomas Classes · Answer

Given expression for velocity of projection\ $\overline{\mathrm{v}}=3 \mathrm{i}+4.9 \mathrm{j}-------(1)$\ General expression for velocity.\ General expression for velocity of projection $$ \begin{equation*} \overline{\mathbf{v}}=(\mathbf{u} \cos 	heta) \mathbf{i}+(\mathbf{u} \sin 	heta) \mathbf{j} 	ag{2} \end{equation*} $$ Comparing (1) and (2)\ $	herefore \mathrm{u} \cos 	heta=3$\ $\mathrm{u} \sin 	heta=4.9$\ $\mathrm{t}=\frac{2(\mathrm{u} \sin 	heta)}{\mathrm{g}}=\frac{2 	imes 4.9}{9.8}=1 \mathrm{~s}$\ $\mathrm{H}=\frac{\mathrm{u}^{2} \sin ^{2} 	heta}{\mathrm{~g}}=\frac{(\mathrm{u} \sin 	heta)^{2}}{2 \mathrm{~g}}=\frac{4.9 	imes 4.9}{2 	imes 9.8}$\ $=$\ $\mathrm{R}=\frac{\mathrm{u}^{2} 2 \sin 	heta \cos 	heta}{\mathrm{~g}}$ $$ \begin{aligned} & =\frac{2(u \sin 	heta)(u \cos 	heta)}{g} \ & =\frac{2 	imes 3 	imes 4.9}{9.8} \end{aligned} $$